Aluminum alloy core material, aluminum alloy core, copper-aluminum composite bar and preparation method of copper-aluminum composite bar

Abstract

The invention discloses the technical field of copper-clad aluminum composite materials, and particularly discloses an aluminum alloy core material, an aluminum alloy core, a copper-aluminum composite bar and a preparation method of the copper-aluminum composite bar, and the aluminum alloy core material comprises, by mass, 0.26%-0.8% of iron, 0.03%-0.3% of copper, 0.001%-0.15% of beryllium and the balance aluminum. The Be-containing aluminum alloy core and the shell copper pipe can form a synergistic conductive structure, so that the mechanical strength and the fatigue resistance of the copper-clad aluminum composite bar are enhanced, and meanwhile, the overall conductive performance of the copper-aluminum continuous casting integrated composite bar is guaranteed. In addition, the thermal expansion coefficient of the Be-containing aluminum alloy is matched with that of the copper layer, interface stress can be reduced, and bonding failure caused by temperature change is avoided.

Description

Technical Field

[0001] This invention belongs to the field of copper-clad aluminum composite material technology, specifically relating to an aluminum alloy core material, an aluminum alloy core, a copper-aluminum composite busbar, and its preparation method. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Copper-aluminum composite busbars are composite conductive busbars that permanently metallurgically combine copper layers and aluminum cores. They combine the high conductivity of copper with the lightweight characteristics of aluminum. If they replace traditional copper busbars while ensuring safe and reliable service, they can achieve a comprehensive cost reduction of more than 30% and copper savings of more than 55%. They can be widely used in core power transmission and distribution scenarios such as substations and switchgear, fundamentally avoiding the electrochemical corrosion risk caused by poor interface contact in traditional copper-aluminum transition joints.

[0004] Current research on copper-aluminum composite busbars mainly focuses on optimizing the metallurgical bonding strength and uniformity of the copper-aluminum interface. However, systematic research on optimizing the composition and microstructure of aluminum and aluminum alloy cores to simultaneously improve the mechanical properties and conductivity of copper-clad aluminum composite busbars is still lacking, which restricts their widespread application in demanding power scenarios.

[0005] Furthermore, copper has a smaller coefficient of linear expansion than aluminum. When temperatures change, aluminum expands and contracts more than copper. This inconsistent expansion and contraction is constrained by the strong metallurgical bond between the two, generating significant internal thermal stress. If this thermal stress exceeds the strength of the copper-aluminum interface, interface failure occurs, manifesting as microscopic separation at weaker points, forming small bulges. In severe cases, the copper and aluminum layers separate over large areas, completely destroying the structural integrity of the composite busbar. Once delamination occurs, the conductivity of the composite busbar drops sharply, its mechanical strength is lost, and it may experience localized overheating due to poor contact, ultimately leading to failure.

[0006] Furthermore, asymmetrical expansion / contraction occurs not only in the thickness direction but also in the length and width directions. For longer copper-aluminum composite busbars, uneven internal stress after temperature cycling can cause warping. Warped busbars cannot be installed flat in switch cabinets or battery boxes; bending leads to uneven contact pressure at bolt connection points, increasing contact resistance and causing overheating; it may also collide with other components or cause short circuits; even if the composite busbar itself does not delaminate, temperature changes can affect its connection to external terminals. For example, a copper terminal is bolted to the copper surface of a copper-aluminum composite busbar. When the temperature changes, the overall expansion and contraction of the composite busbar differs from that of a pure copper terminal. This slight difference generates additional stress at the bolt connection, potentially causing bolt loosening, decreased contact pressure, increased contact resistance, and the formation of hot spots.

[0007] If the equipment requires frequent start-stop operations or experiences significant load fluctuations (such as acceleration and braking in electric vehicles), the copper-aluminum composite busbar will continuously undergo temperature cycling. The internal thermal stress will also cycle accordingly. This alternating stress can lead to material fatigue. Even if the stress does not reach the point of initial failure, after multiple cycles, microcracks will form at the interface and gradually propagate, eventually leading to fatigue fracture or delamination. This is a key factor affecting the long-term service life of the product.

[0008] However, existing technologies still struggle to effectively address the significant difference in the coefficients of linear expansion between the copper layer and the aluminum alloy core in copper-aluminum composite busbars. Summary of the Invention To address the shortcomings of existing technologies, the present invention aims to provide an aluminum alloy core material for preparing copper-aluminum composite busbars, an aluminum alloy core, a copper-aluminum composite busbar, and a method for preparing the same. By adding beryllium, the strength and conductivity of the aluminum alloy core are improved, and the coefficient of linear expansion of the aluminum alloy core is adjusted to match that of the copper layer, thereby improving the overall performance of the copper-aluminum composite busbar.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides an aluminum alloy core material, comprising the following components by mass percentage: 0.26%-0.8% iron, 0.03%-0.3% copper, 0.001%-0.15% beryllium, with the balance being aluminum.

[0010] Secondly, the present invention provides an aluminum alloy core, which is made from the aluminum alloy core material.

[0011] Thirdly, the present invention provides a method for preparing the aluminum alloy core, comprising the following steps: Prepare the ingredients according to the formula of the aluminum alloy core material; The prepared raw materials are refined. The refining process involves first raising the temperature of the raw materials to 450-550℃ and holding it at that temperature for 0.5-1.5 hours; then raising the temperature to 760℃~800℃, during which a refining agent is added to remove gas and impurities. The refined and qualified aluminum melt is shaped into an aluminum alloy core.

[0012] Fourthly, the present invention provides a copper-aluminum composite busbar, wherein the outer shell is a copper tube and the inner core is the aforementioned aluminum alloy core.

[0013] Fifthly, the present invention provides a method for preparing the copper-aluminum composite busbar, comprising the following steps: The aluminum melt, smelted using the aluminum alloy core material, is uniformly and continuously poured into the solidified cladding copper tube. After solidification, the resulting copper-aluminum composite material is drawn, rolled, and annealed to obtain the final product. Alternatively, physical pressure can be used to coat the pre-prepared aluminum alloy core with a copper plate or copper tube.

[0014] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: Doping aluminum alloys with trace amounts of Cu can precisely optimize their mechanical properties, corrosion resistance, and processability through mechanisms such as solid solution strengthening, regulation of aging behavior, and improvement of interfacial bonding, thereby achieving a balance between strength and plasticity.

[0015] By introducing a certain amount of Fe into aluminum alloys, which has a different strengthening effect than Cu, it can refine grains, regulate the microstructure of aluminum alloys, improve casting properties such as the flow of the core, purify trace impurities in aluminum and reduce their harmfulness, and enhance the high-temperature stability of the alloy.

[0016] The microstructure of the prepared Be-containing aluminum alloy is fibrous, with a fine and densely distributed second phase. The average size and average spacing of the fibers are small, which can synergistically improve tensile strength, electrical conductivity and plasticity. Its tensile strength can reach 160MPa-178MPa and its electrical conductivity can reach 53%-56% IACS.

[0017] The be-containing aluminum alloy core and the outer copper tube form a synergistic conductive structure, enhancing the mechanical strength and fatigue resistance of the copper-clad aluminum composite busbar, while ensuring the overall conductivity of the integrated copper-aluminum continuous casting composite busbar. Furthermore, in the aluminum alloy of this invention, Cu, Fe, and Be work synergistically to adjust the coefficient of thermal expansion of the aluminum alloy, matching it with the copper layer. This reduces interfacial stress and prevents bonding failure due to temperature changes, which is a key foundation for ensuring the long-term stable operation of the copper-clad aluminum composite busbar. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a production process flow diagram of Embodiment 1 of the present invention; Figure 2 This is a microstructure diagram of the Be-containing aluminum alloy prepared in Example 1 of the present invention. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] As described in the background section, there is still a lack of systematic research on the optimization of the composition and microstructure of aluminum and aluminum alloy cores in copper-clad aluminum composite busbars to simultaneously improve the mechanical properties and conductivity of copper-clad aluminum composite busbars. Furthermore, there are problems such as the different coefficients of linear expansion between the aluminum core and the copper shell, which lead to interface failure, warping, increased contact resistance at bolt connections, and material fatigue.

[0022] In a first aspect, the present invention provides an aluminum alloy core material for preparing copper-aluminum composite busbars, comprising the following components by mass percentage: 0.26%-0.8% iron, 0.03%-0.3% copper, 0.001%-0.15% beryllium, and the balance being aluminum.

[0023] Benzene (Be) has a small atomic radius and a high melting point and elastic modulus. When added to aluminum alloys along with alloying elements such as Fe and Cu, it can balance the effects of alloy composition and intermetallic compounds on electrical conductivity, increasing the alloy's ductility and creep resistance, and reducing its cracking tendency. Simultaneously, it refines the aluminum alloy grain size, improving its mechanical properties such as tensile strength. In the preparation of copper-clad aluminum composite materials using aluminum alloy cores and copper tubes, the added trace elements adjust the characteristics of the core aluminum alloy and can appropriately compensate for any decrease in conductivity, comprehensively improving the various properties of the core aluminum alloy.

[0024] In some embodiments, the aluminum alloy core material comprises, by mass percentage, the following components: 0.4%-0.8% iron, 0.1%-0.3% copper, 0.01%-0.1% beryllium, with the balance being aluminum.

[0025] Preferably, the aluminum alloy core material comprises, by mass percentage, the following components: 0.4%-0.6% iron, 0.1%-0.2% copper, 0.03%-0.1% beryllium, with the balance being aluminum.

[0026] Secondly, the present invention provides an aluminum alloy core, which is made from the aluminum alloy core material.

[0027] Thirdly, the present invention provides a method for preparing the aluminum alloy core, comprising the following steps: Prepare the materials according to the specified proportions for the aluminum alloy core material; The prepared raw materials are refined. The refining process involves first raising the temperature of the raw materials to 450-550℃ and holding it at that temperature for 0.5-1.5 hours; then raising the temperature to 760℃~800℃, during which a refining agent is added to remove gas and impurities. The refined and qualified aluminum melt is shaped into an aluminum alloy core.

[0028] In some embodiments, the raw material for providing iron is Al-20Fe; the raw material for providing copper is Al-50Cu; and the raw material for providing beryllium is Al-3Be.

[0029] In some embodiments, the refining agent includes chloride salts and fluoride salts.

[0030] In some embodiments, the forming process includes the following steps: cleaning, primary rolling, and continuous rolling of the ingot obtained by casting molten aluminum to obtain an aluminum rod; The aluminum rod is cleaned, cooled, dried, solution-treated, and aged to obtain an aluminum alloy core.

[0031] Preferably, the roll pass system used in the continuous rolling process is rhombus-circle-rhombus-circle-rhombus-circle.

[0032] Preferably, the solution temperature is 500-600℃ and the solution time is 20-40 min; the aging treatment temperature is 150-210℃ and the time is 8-15 h.

[0033] Fourthly, the present invention provides a copper-aluminum composite busbar, wherein the outer shell is a copper tube and the inner core is the aforementioned aluminum alloy core.

[0034] Fifthly, the present invention provides a method for preparing the copper-aluminum composite busbar, comprising the following steps: The aluminum melt, smelted using the aluminum alloy core material, is uniformly and continuously poured into the solidified cladding copper tube. After solidification, the resulting copper-aluminum composite material is drawn, rolled, and annealed to obtain the final product. Alternatively, physical pressure can be used to coat the pre-prepared aluminum alloy core with a copper plate or copper tube.

[0035] In some embodiments, the forming rate is 75-90 mm / min.

[0036] In some embodiments, the rolling is a four-pass roll.

[0037] In some embodiments, the annealing temperature is 200-300°C and the annealing time is 50-70 min.

[0038] The copper-aluminum continuous casting integrated composite bar prepared by the present invention has a tensile strength of over 185 MPa and a conductivity of not less than 70% IACS.

[0039] The production method of the present invention will be described in detail below with reference to specific embodiments to help understand the content of the present invention.

[0040] Example 1 An aluminum alloy core material for copper-aluminum composite busbars, wherein the mass percentages of each component in the aluminum alloy are: Fe 0.53%, Cu 0.17%, Be 0.05%, with the balance being Al.

[0041] The method for preparing an aluminum alloy core using the aforementioned aluminum alloy core material includes the following steps: First, high-purity aluminum, Al-20Fe, Al-50Cu and Al-3Be are placed at the bottom of an intermediate frequency furnace. When the furnace temperature reaches 500℃, this temperature is maintained for 20 minutes for refining. Then, the temperature is raised to 800℃. After the aluminum alloy melt in the intermediate frequency furnace is fully mixed, a refining agent composed of chloride salts and fluoride salts is added to degas and remove impurities. The mixture is then held at this temperature for 30 minutes to obtain the aluminum melt. The slag on the surface of the molten aluminum is removed, and then the remaining molten aluminum is poured into the tundish. The molten aluminum in the tundish enters the casting wheel evenly for continuous crystallization to obtain an ingot. The obtained billet is removed from the casting wheel by the ingot remover. After cleaning, the billet is fed into the primary rolling mill by the guide device. The primary rolling has a processing rate of 86%. The billet after initial rolling is subjected to six consecutive rolling passes using a rhombus-circular-rhombus-circular-rhombus-circular pass system, with a total processing rate of 86%, producing aluminum rods with a diameter of 10mm. The rolled aluminum rods are cleaned and cooled through cooling pipes, and the temperature is lowered to below 80°C. Then, they are dried through compressed air nozzles. Then, a well-type resistance heating furnace was used for solution treatment at a temperature of 550℃ for 30 minutes, and the cooling method was hot water quenching. Finally, an aging treatment was carried out using a box-type resistance heating furnace at an aging temperature of 180℃ for 9 hours, with air cooling to obtain the aluminum rod.

[0042] Example 2 An aluminum alloy core material for copper-aluminum composite busbars, wherein the weight percentages of each component in the aluminum alloy are Fe 0.53%, Cu 0.17%, Be 0.1%, and the balance is Al.

[0043] The method for preparing an aluminum alloy core using the aforementioned aluminum alloy core material includes the following steps: First, place high-purity aluminum Al-20Fe, Al-50Cu, and Al-3Be at the bottom of a medium-frequency electric furnace. When the furnace temperature reaches 500℃, maintain this temperature for refining for 20 minutes, and then continue to raise the temperature to 800℃. After the aluminum alloy melt in the medium frequency electric furnace is fully and evenly mixed, a refining agent composed of chloride salts and fluoride salts is added to remove gas and impurities. The mixture is then held at the temperature for 30 minutes to obtain the aluminum melt. The slag on the surface of the molten aluminum is removed, and then the remaining molten aluminum is poured into a tundish. The molten aluminum in the tundish enters the casting wheel evenly for continuous crystallization to obtain an ingot. The obtained billet is removed from the casting wheel by the ingot remover; after cleaning, the billet is fed into the primary rolling mill by the guide device, and the primary rolling has a processing rate of 86%. The billet after initial rolling is subjected to 6 consecutive rolling passes, using a rhombus-circle-rhombus-circle-rhombus-circle system, with a total processing rate of 86%, and produces an aluminum rod with a diameter of 10mm. The rolled aluminum rods are cleaned and cooled through cooling pipes, and the temperature is lowered to below 80°C. Then, they are dried through compressed air nozzles. Solution treatment was performed using a well-type resistance heating furnace at a temperature of 550℃ for 30 minutes, followed by hot water quenching. After solution treatment for 12 hours, aging treatment was carried out in a box-type resistance heating furnace at an aging temperature of 210℃ for 12 hours, and air cooling was used.

[0044] Example 3 An aluminum alloy core material for copper-aluminum composite busbars, wherein the weight percentages of the components in the aluminum alloy are Fe 0.67%, Cu 0.25%, Be 0.15%, and the balance is Al.

[0045] The method for preparing an aluminum alloy core using the aforementioned aluminum alloy core material includes the following steps: First, place high-purity aluminum Al-20Fe, Al-50Cu and Al-3Be at the bottom of the medium-frequency electric furnace. When the furnace temperature reaches 520℃, maintain this temperature for 20 minutes to refine, and then continue to raise the temperature to 780℃. After the aluminum alloy melt in the medium frequency electric furnace is fully and evenly mixed, a refining agent composed of chloride salts and fluoride salts is added to remove gas and impurities. The mixture is then held at the temperature for 30 minutes to obtain the aluminum melt. The slag on the surface of the molten aluminum is removed, and then the remaining molten aluminum is poured into a tundish. The molten aluminum in the tundish enters the casting wheel evenly for continuous crystallization to obtain an ingot. The obtained billet is removed from the casting wheel by the ingot remover; after cleaning, the billet is fed into the primary rolling mill by the guide device, and the primary rolling has a processing rate of 86%. The billet after initial rolling is subjected to 6 consecutive rolling passes, using a rhombus-circle-rhombus-circle-rhombus-circle system, with a total processing rate of 86%, and produces an aluminum rod with a diameter of 10mm. The rolled aluminum rods are cleaned and cooled through cooling pipes, and the temperature is lowered to below 80°C. Then, they are dried through compressed air nozzles. Solution treatment was performed using a well-type resistance heating furnace at a temperature of 600℃ for 20 minutes, followed by hot water quenching. After solution treatment for 12 hours, aging treatment was carried out in a box-type resistance heating furnace at an aging temperature of 170℃ for 10 hours, and air cooling was used.

[0046] Example 4 The aluminum alloy core material for copper-aluminum composite busbars used in Example 1 has the following mass percentages: Fe 0.53%, Cu 0.17%, Be 0.05%, with the balance being Al.

[0047] When preparing copper-aluminum composite bars using solid-liquid combination methods such as core-filled continuous casting, only two steps are required: batching and smelting. This provides high-temperature molten aluminum liquid for the subsequent continuous casting composite process, as detailed below: 1. Batching: Mix 99.999% high-purity aluminum, Al-20Fe, Al-50Cu and Al-3Be master alloy and other raw materials according to the component ratio; 2. Melting: The prepared raw materials are added to a crucible and refined using a medium-frequency electric furnace. A thermocouple is inserted into the crucible, and the temperature of the temperature controller is adjusted to 500℃. After the temperature reaches 500℃, it is held for 20 minutes. Then, the temperature is raised to 800℃. After the aluminum alloy melt in the medium-frequency furnace is fully mixed, a refining agent composed of chloride and fluoride salts is added to degas and remove impurities. The mixture is held for 30 minutes to obtain aluminum melt. The refined aluminum melt flows into a tundish through a trough. The temperature inside the tundish is 800℃. 3. Filling: The molten aluminum in the tundish is uniformly and continuously filled into the solidified cladding copper tube to obtain a copper-aluminum composite material; 4. The prepared copper-aluminum composite material is drawn into a billet at a speed of 80 mm / min using a traction mechanism to obtain a copper-aluminum continuous casting integrated composite billet with uniform cladding, continuous aluminum core, and no macroscopic casting defects. Then, the copper-aluminum billet is rolled in four passes to produce a copper-aluminum composite busbar with good uniformity of copper layer thickness distribution. The copper layer thickness is 1.5 mm, and the copper layer accounts for 25% of the volume of the copper-aluminum composite busbar. 5. Anneal the copper-aluminum composite array at 300℃ for 60 minutes.

[0048] Example 5 The copper-aluminum composite busbar was prepared using the aluminum alloy core material of Example 2, and the preparation method was the same as that of Example 4.

[0049] Example 6 The copper-aluminum composite busbar was prepared using the aluminum alloy core material of Example 3, and the preparation method was the same as that of Example 4.

[0050] Comparative Example 1 The difference from Example 1 is that Be is replaced with Cu, while everything else is the same as in Example 1.

[0051] Comparative Example 2 The difference from Example 1 is that the Be content is 0.5%, while everything else is the same as in Example 1.

[0052] Comparative Example 3 The difference from Example 1 is that Fe is replaced with Cu, while everything else is the same as in Example 1.

[0053] Comparative Example 4 The difference from Example 1 is that Cu is replaced with Fe, while everything else is the same as in Example 1.

[0054] Comparative Example 5 The difference from Example 1 is that the copper content is 0.6%, while everything else is the same as in Example 1.

[0055] Comparative Example 6 The difference from Example 1 is that the iron content is 1%, while everything else is the same as in Example 1.

[0056] Comparative Example 7 A copper-aluminum composite busbar was prepared using the aluminum alloy core material of Comparative Example 1, and the preparation method was the same as in Example 4.

[0057] Comparative Example 8 A copper-aluminum composite busbar was prepared using the aluminum alloy core material of Comparative Example 2, and the preparation method was the same as in Example 4.

[0058] Comparative Example 9 A copper-aluminum composite busbar was prepared using the aluminum alloy core material of Comparative Example 3, and the preparation method was the same as in Example 4.

[0059] Comparative Example 10 A copper-aluminum composite busbar was prepared using the aluminum alloy core material of Comparative Example 4, and the preparation method was the same as in Example 4.

[0060] Comparative Example 11 A copper-aluminum composite busbar was prepared using the aluminum alloy core material of Comparative Example 5, and the preparation method was the same as in Example 4.

[0061] Comparative Example 12 A copper-aluminum composite busbar was prepared using the aluminum alloy core material of Comparative Example 6, and the preparation method was the same as in Example 4.

[0062] The properties of the aluminum alloy cores prepared in Examples 1-3 and Comparative Examples 1-6 are shown in Table 1: Table 1 Properties of high-strength, high-conductivity aluminum alloys containing Be

[0063] The properties of the copper-aluminum composite busbars prepared in Examples 4-6 and Comparative Examples 7-12 are shown in Table 2: Table 2 Performance of Copper-Aluminum Composite Busbar

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An aluminum alloy core material for preparing copper-aluminum composite busbars, characterized in that: By mass percentage, it includes the following components: 0.26%-0.8% iron, 0.03%-0.3% copper, 0.001%-0.15% beryllium, and the balance is aluminum.

2. The aluminum alloy core material according to claim 1, characterized in that: By mass percentage, it includes the following components: 0.4%-0.8% iron, 0.1%-0.3% copper, 0.01%-0.1% beryllium, and the balance is aluminum.

3. The aluminum alloy core material according to claim 2, characterized in that: The aluminum alloy core material comprises, by mass percentage, the following components: 0.4%-0.6% iron, 0.1%-0.2% copper, 0.03%-0.1% beryllium, with the balance being aluminum.

4. An aluminum alloy core, characterized in that: It is made from the aluminum alloy core material described in any one of claims 1-3.

5. The method for preparing the aluminum alloy core according to any one of claims 1-4, characterized in that: Includes the following steps: Prepare the ingredients according to the formula of the aluminum alloy core material; The prepared raw materials are refined. The refining process involves first raising the temperature of the raw materials to 450-550℃ and holding it at that temperature for 0.5-1.5 hours; then raising the temperature to 760℃~800℃, during which a refining agent is added to remove gas and impurities. The refined and qualified aluminum melt is shaped into an aluminum alloy core.

6. The method for preparing the aluminum alloy core according to claim 5, characterized in that: The forming process includes the following steps: the ingot obtained by casting molten aluminum is cleaned, pre-rolled, and continuously rolled to obtain an aluminum rod; The aluminum rod is cleaned, cooled, dried, solution-treated, and aged to obtain an aluminum alloy core.

7. The method for preparing the aluminum alloy core according to claim 6, characterized in that: During continuous rolling, the roll pass system used is rhombus-circle-rhombus-circle-rhombus-circle.

8. The method for preparing the aluminum alloy core according to claim 5, characterized in that: The solution treatment temperature is 500-600℃ and the solution treatment time is 20-40 min; the aging treatment temperature is 150-210℃ and the time is 8-15 h.

9. A copper-aluminum composite bar, characterized in that: Its outer shell is a copper tube, and its inner core is the aluminum alloy core described in claim 4.

10. The method for preparing the copper-aluminum composite busbar according to claim 9, characterized in that: Includes the following steps: The aluminum melt, smelted using any one of the aluminum alloy core materials described in claims 1-3, is uniformly and continuously poured into the solidified cladding copper tube. After solidification, the resulting copper-aluminum composite material is drawn, rolled, and annealed to obtain the final product. Alternatively, physical pressure can be used to coat the pre-prepared aluminum alloy core with a copper plate or copper tube.

Images